Molecular Genotyping of the Human Cystic Echinococcosis in Mazandaran Province, North of Iran

Abstract

Background: The larval stage of the tapeworm (cestode) Echinococcus granulosus is the etiological agent of hydatidosis or cystic echinococcosis, which is the zoonotic parasitic disease causing morbidity and mortality in both humans and livestock. Due to a lack of accurate data on the human isolates of E. granulosus in Mazandaran Province, northern Iran, the current study aimed to survey the population genetic pattern of cystic echinococcosis isolated from humans by sequencing the mitochondrial genes of NADH dehydrogenase subunit 1 (nad1).

Methods: Overall, 47 formalin fixed paraffin-embedded tissue (FFPT) blocks were collected from patients' files in various pathology departments of Mazandaran Province in Iran from 2003 to 2015. PCR was performed to amplify a 398bp DNA fragment of mitochondrial nad1. PCR products were sequenced by Bioneer Corporation (South Korea), and the resulting data were analyzed via relevant software to determine the genotypes.

Results: The nad1 gene was successfully amplified on 10 from all of the E. granulosus isolates. Overall, 66.6% and 33.3% of the isolates in the studied area displayed the G1 and G2-G3 genotypes, respectively.

Conclusion: This study may provide the foundation for further studies in revealing the regional transmission patterns and also in designing adequate control procedures.

Keywords: Echinococcus granulosus; Iran; Molecular characterization; NADH dehydrogenase 1.

Fig. 1:

PCR amplified nad1 fragments from human isolates of E. granulosus from Mazandaran, Iran. Ladder 100bp, lan1: negative control, lane 2–5: Positive sample

Fig. 2:

Genetic relationships of E. granulosus human isolates from Mazandaran Province (North of Iran) and reference sequences for E. granulosus sensu stricto and Taenia saginata as the out group. The relationships were inferred based on the phylogenetic analysis of the concatenated nad1 sequence data (E7–E12). All haplotypes represent genotypes G1–G3 (G1–G3 complex, E. granulosus sensu stricto)